1. Field of the Invention
This invention relates to a sheet sub-stack separating and feeding apparatus for taking out sheet sub-stacks each comprising a predetermined number of sheets from a stack of the sheets one at a time.
2. Description of the Prior Art
In many cases, sheet materials such as paper sheets and thin metal plates are fabricated, for example, by cutting a web of these materials in predetermined lengths, and then laid one upon the other to form a stack by matching the positions for use in the next process such as sheet loading or packaging. When packaging or the like is carried out after the sheet materials are disposed in a stack, it is necessary to take out sheet sub-stacks each comprising a predetermined number of sheets (for example, one packaging unit of sheets in the case of packaging) from the sheet stack one at a time.
As apparatuses for taking out sheet sub-stacks each comprising a predetermined number of sheets from a sheet stack one at a time as described above, there has heretofore been known an apparatus wherein the uppermost sheet sub-stack of the sheet stack is pushed out approximately horizontally by a pusher, and the pushed-out sheet stack is placed on a conveying means such as a roller conveyor and separated from the sheet stack. However, in the sheet sub-stack separating and feeding apparatus using the pusher, it is necessary in advance to bundle the predetermined numbers of sheets constituting sub-stacks by use of tapes or the like and lay the sub-stacks one upon the other so that the sheets constituting each sub-stack will not be thrown out of order when they are pushed out by the pusher. Bundling the sheets at the time of stacking the sheets one by one requires considerable labor, a mechanism or a means therefor, and a longer time for stacking the sheets.